Cabinet Requirements; Cabinet Size And Clearance Requirements; Cabinet Airflow Requirements - Juniper MX240 Hardware Manual

MX240 Ethernet Services Router Hardware Guide
Table 19: Site Preparation Checklist (continued)
Item or Task
Calculate the optical power budget and optical
power margin.

Cabinet Requirements

The router can be installed in a standard 482-mm wide (or larger) enclosed cabinet.
The following sections describe cabinet requirements:

Cabinet Size and Clearance Requirements

The minimum-sized cabinet that can accommodate the router is 482-mm wide and
800-mm deep. A cabinet larger than the minimum requirement provides better
airflow and reduces the chance of overheating. To accommodate a single router, the
cabinet must be at least 13 U high. If you provide adequate cooling air and airflow
clearance, you can stack several routers in a cabinet that has sufficient usable vertical
space. Each router requires 5 U.
The minimum total clearance inside the cabinet is 30.7 in. between the inside of the
front door and the inside of the rear door.

Cabinet Airflow Requirements

When you mount the router in a cabinet, you must ensure that ventilation through
the cabinet is sufficient to prevent overheating. Consider the following requirements
to when planning for chassis cooling:
30
Cabinet Requirements
For More Information
"Calculating Power Budget for
Fiber-Optic Cable" on page 181
Cabinet Size and Clearance Requirements on page 30
Cabinet Airflow Requirements on page 30
Ensure that the cool air supply you provide through the cabinet can adequately
dissipate the thermal output of the router.
Ensure that the cabinet allows the chassis hot exhaust air to exit from the cabinet
without recirculating into the router. An open cabinet (without a top or doors)
that employs hot air exhaust extraction from the top allows the best airflow
through the chassis. If the cabinet contains a top or doors, perforations in these
elements assist with removing the hot air exhaust. For an illustration of chassis
airflow, see Figure 17 on page 25.
Install the router as close as possible to the front of the cabinet so that the cable
management system just clears the inside of the front door. This maximizes the
clearance in the rear of the cabinet for critical airflow.
Route and dress all cables to minimize the blockage of airflow to and from the
chassis.
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